Surgical management of a canine intracranial abscess due to a bite wound

OBJECTIVE

To describe the successful surgical management of a brain abscess in a dog secondary to bite wound.

CASE SUMMARY

A 10-year-old neutered female Welsh Corgi/Chihuahua, weighing 5.3 kg, was presented for evaluation of seizures, ataxia, and falling to the left 8 days after a presumptive fight with another dog. On examination at presentation, the dog was alert, responsive, and ambulatory with tetra-ataxia, falling to the left, left-sided postural deficits, and absent left menace response. Within 24 hours, the dog progressed to nonambulatory tetraparesis with minimal motor, absent postural reactions of all limbs, left nasal hypalgesia, reduced gag reflex, and depressed mentation. Computed tomographic images of the brain were suggestive of a bite wound fracture of the right parietal bone with secondary meningoencephalitis, right parietal lobe abscessation, and white matter edema adjacent to the bone fracture. A modified right rostrotentorial craniectomy was performed, the abscess was identified, contents of the abscess were removed, and the surgical site was flushed extensively before closing. Corynebacterium spp. was cultured from within the abscess. Within hours of surgery, the dog was quiet but alert, responsive, and sitting up in her cage. In addition to surgical intervention, intensive care, broad-spectrum IV antimicrobials, and supportive therapy led to significant neurologic improvement with only occasional seizures and mild postural reaction deficits of the left hindlimb remaining.

NEW OR UNIQUE INFORMATION PROVIDED

Abscess formation within the CNS is uncommon in dogs and cats and is associated with a high mortality rate. In veterinary medicine the management of brain abscesses is controversial with limited information available regarding treatment. This is the first case report that demonstrates surgical intervention in combination with antimicrobial therapy can be used successfully in the treatment of a canine brain abscess.

The wobbly cat. Diagnostic and therapeutic approach to generalised ataxia

PRACTICAL RELEVANCE

Generalised ataxia is one of the most common neurological presentations identified in cats in practice. The causes can be subdivided into three forms on the basis of the neuroanatomical diagnosis: cerebellar, vestibular and sensory (spinal or general proprioceptive) ataxia. The type of ataxia will determine the diagnostic procedures and select the differential diagnoses, and an accurate neuroanatomical diagnosis is therefore essential. The differential diagnosis list can then be further tailored on the basis of patient signalment, clinical presentation and progression.

GLOBAL IMPORTANCE

Irrespective of the world region, most of the causes of generalised ataxia in the cat are similar and many have been identified for a number of years (cerebellar hypoplasia has been recognised since the late 19th century). However, it is the advent of new technology, in particular veterinary access to magnetic resonance imaging, which has resulted in particularly rapid advances in our understanding, investigation and management of these different forms of ataxia.

AUDIENCE

This article introduces the classification of patients with ataxia on the basis of their clinical presentation, discusses the common differential diagnoses associated with each form, and briefly reviews the more important diseases from a clinical perspective. It is aimed at all veterinarians who treat cats.

Cerebrospinal Fluid

This chapter discusses the anatomy, functions, and biochemistry of cerebrospinal fluid (CSF). CSF has four major functions: physical support of neural structures, excretion and “sink” action, intracerebral transport, and control of the chemical environment of the central nervous system. CSF provides a “water jacket” of physical support and buoyancy. The CSF is protective because its volume changes reciprocally with changes in the volume of intracranial contents, particularly blood. Thus, the CSF protects the brain from changes in arterial and central venous pressure associated with posture, respiration, and exertion. Acute or chronic pathological changes in intracranial contents can be accommodated, to a point, by changes in the CSF volume. The direct transfer of brain metabolites into the CSF provides excretory function. This capacity is important because the brain lacks a lymphatic system. The lymphatic function of the CSF is also manifested in the removal of large proteins and cells, such as bacteria or blood cells, by bulk CSF absorption. The “sink” action of the CSF arises from the restricted access of water-soluble substances to the CSF and the low concentration of these solutes in the CSF.